A metallized high power log periodic antenna element, array

Abstract

The application relates to a metalized high-power logarithmic periodic antenna unit and array, and belongs to the technical field of microwave antennas. The antenna unit comprises a feeding coaxial probe, a feeding connection copper block, a metal feeding line and a metal logarithmic periodic dipole structure; the antenna as a whole adopts a full-metal structure without a dielectric plate, and the feeding mode adopts the metal feeding line taking air as the medium, so that the heat dissipation capacity and power capacity of the antenna are improved; the lengths of the antenna dipoles gradually increase from high to low, the dipole arms are folded inwards by 45 degrees with the set line as the central axis in the vertical plane, finally all the dipoles are located on two mutually perpendicular planes, and on the basis of the bottom several groups of dipole arms, the dipole arms are further bent by 90 degrees twice in the vertical direction to form C-shaped dipole arms; the structure effectively reduces the transverse size of the antenna unit, the coupling current between the array elements in the antenna array can be utilized to expand the antenna bandwidth to the low frequency. The application has the advantages of large antenna power capacity, small antenna unit and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microwave antennas, in particular to a metalized high-power logarithmic periodic antenna unit and array, which mainly solves the problems of low power capacity and large unit size of the logarithmic periodic antenna, and can be applied to high-power electronic countermeasure array antennas. BACKGROUND

[0002] Logarithmic periodic antenna is a wideband antenna proposed and developed in the late 1950s. Its electrical characteristics change periodically with the logarithm of frequency, and remain basically unchanged in a very wide frequency band. Its structure has been greatly developed since its inception. Logarithmic periodic antenna has the following characteristics: 1. It has an ultra-wide band, usually up to 3 times or more; 2. The gain curve is flat within the operating bandwidth; 3. Increasing the number of dipoles can improve the antenna gain and bandwidth; 4. The structure is simple and easy to process. Therefore, the logarithmic periodic antenna has a good application prospect in wideband array antennas. However, most traditional logarithmic periodic antennas use dielectric plate printing or coaxial line top feeding, which results in a low upper limit of the antenna power capacity and a too long transverse size of the dipole arm, limiting its application in wideband array antennas. Therefore, designing a logarithmic periodic antenna with high power capacity and small unit size has broad application prospects.

[0003] The patent document with publication number CN115275576 discloses a "logarithmic periodic antenna based on folded dipoles". This antenna uses F4B as the dielectric substrate, and is fed by connecting the metal patch at the short dipole to the parallel double lines on one side of the substrate. The invention makes a number of metal vias on the dielectric substrate, and the metal vias are axially parallel to the antenna axis. The antenna dipoles pass through the metal vias in turn, achieving multiple folding of the antenna in three-dimensional space and reducing the transverse size of the antenna. Since the dielectric substrate is very thin and the breakdown voltage of the dielectric is much lower than that of air, the power capacity of the antenna is relatively low.

[0004] Wang Zijuan mentioned a metal logarithmic periodic antenna in her published paper "Miniaturization of Logarithmic Periodic Dipole Antenna" (Master's Degree Thesis of National University of Defense Technology, 2020). The copper plate with a thickness of 1.5 mm is cut into a shape to form this antenna. The feed line used in this antenna is a coaxial line, which connects the upper part of the collection line to the outer conductor of the coaxial line, and the inner core of the coaxial line is connected to a copper screw, which has electrical contact with the lower half of the collection line but not with the upper half. This invention effectively improves the power capacity of the antenna by using a copper plate as the main body of the antenna. However, since the feed part uses coaxial feeding, the coaxial line is integrated on the antenna collection line, which still limits the power capacity of the antenna. SUMMARY

[0005] The technical problems to be solved by the present application are:

[0006] In order to avoid the shortcomings of the prior art, the present application provides a metalized high-power log-periodic antenna unit and array, which is used to solve the problems of low power capacity and large unit size of the existing log-periodic antenna.

[0007] In order to solve the above technical problems, the technical scheme adopted by the present application is:

[0008] A metalized high-power log-periodic antenna unit, characterized in that it comprises a metal antenna main body, a feed coaxial probe, a mounting flange, a feed connection copper block and a metal feed line.

[0009] The metal antenna main body comprises an outer metal antenna main body and an inner metal antenna main body, which have the same structure and both comprise a collection line and antenna dipoles on both sides of the collection line; the antenna dipoles of the outer metal antenna main body and the antenna dipoles of the inner metal antenna main body form a 90° angle.

[0010] The mounting flange comprises an outer mounting flange and an inner mounting flange, which are connected and fixed by metal screws and a metal ring; wherein the outer metal antenna main body is vertically located on the outer mounting flange, and the inner metal antenna main body is vertically located on the inner mounting flange.

[0011] The feed coaxial probe is connected with the feed connection copper block through the outer mounting flange, one end of the metal feed line is connected with the feed connection copper block, and the other end is connected with the top end of the metal antenna main body to feed the metal antenna main body.

[0012] Further technical solutions of the present application: the antenna dipoles of the outer metal antenna main body and the antenna dipoles of the inner metal antenna main body gradually increase in length from high to low, and the bottom several groups of antenna dipoles are bent twice by 90 degrees to form a "C" type dipole arm.

[0013] Further technical solutions of the present application: the metal feed line uses air as the feed line medium, extends to the top of the antenna, and after being bent twice by 90 degrees, forms an electrical connection with the inner metal antenna main body through metal screws to feed the antenna from the top of the antenna.

[0014] Further technical solutions of the present application: the feed connection copper block is welded on the solder pad of the metal feed line located on the outer mounting flange.

[0015] Further technical solutions of the present application: it further comprises a heat-resistant medium screw, which is used to fix the metal feed line and the metal antenna main body.

[0016] The further technical scheme of the present application further comprises heat-resistant medium gaskets for supporting, wherein the heat-resistant medium gaskets comprise an outer heat-resistant medium gasket arranged between the metal feed line and the outer metal antenna body and an inner heat-resistant medium gasket arranged between the metal feed line and the inner metal antenna body.

[0017] The further technical scheme of the present application further comprises metal reinforcing ribs, which are long metal strips with an arch-shaped cross section and are fixed on the collection line of the inner metal antenna body and extend from the top of the antenna to the mounting flange.

[0018] The further technical scheme of the present application is that the mounting flange, the metal feed line and the metal antenna body are made of the same metal material, i.e., 304 stainless steel.

[0019] The further technical scheme of the present application is that the mounting flange is provided with a plurality of weight-reducing holes and through holes for weight reduction and screw fixing.

[0020] The metalized high-power log-periodic antenna array is characterized in that it comprises a plurality of the metalized high-power log-periodic antenna units as described above, and the plurality of the metalized high-power log-periodic antenna units are arranged in an array.

[0021] The present application has the following advantages:

[0022] The metalized high-power log-periodic antenna unit and array provided by the present application have the following advantages compared with the prior art:

[0023] First, the present application uses a full-metal structure antenna instead of a dielectric substrate printed antenna as an antenna unit, and uses a metal feed line with air as a medium instead of a dielectric substrate feed line or a coaxial feed, thereby effectively improving the power capacity and heat dissipation capacity of the antenna.

[0024] Second, the present application effectively reduces the lateral size of the antenna by bending the antenna element. The lateral length of a log-periodic antenna is usually about one-half of the lowest wavelength of its working frequency band, and such an antenna size is usually large. The present application bends the element in the horizontal direction to make the element present two mutually perpendicular planes in the horizontal plane, thereby effectively reducing the lateral length of the antenna. Such a bent antenna unit is placed in a large array, and the working bandwidth of the antenna is widened to a low frequency by using the coupling current between the array elements, thereby making the antenna have the potential for application in a large wideband array.

[0025] Thirdly, the application effectively reduces the transverse size of the antenna unit by designing the bottom several groups of vibrator arms to be bent twice by 90 degrees to form C-shaped vibrator arms, and the coupling current between the array elements in the antenna array can be used to expand the antenna bandwidth to a low frequency.

[0026] Fourthly, compared with the conventional miniaturized log-periodic antenna, the miniaturization measures of the application are all based on the bending of the antenna vibrator body without loading any components, which effectively improves the radiation efficiency and gain of the antenna unit.

[0027] The simulation results show that the application has the advantages of higher power capacity and smaller antenna unit, the -10dB array bandwidth of the application can reach 6 times the frequency, the power capacity is greater than 200W, and the transverse size of the antenna is only 48% of that of the conventional log-periodic antenna, and the antenna gain is greater than 7.5dBi in the entire frequency band. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0029] Figure 1 is an exploded view of the antenna unit of the application Figure 1 ;

[0030] Figure 2 is an exploded view of the antenna unit of the application Figure 2 ;

[0031] Figure 3 is a three-view (size) of the antenna unit of the application

[0032] Figure 4 is a comparison diagram of the simulation results of the array and independent unit voltage standing wave ratio of the feed port of the antenna unit of the application

[0033] Figure 5 is a simulation result diagram of the gain of the antenna of the application at each frequency point varying with frequency

[0034] BRIEF DESCRIPTION OF DRAWINGS

[0035] 1-metal antenna body, 2-feed coaxial probe, 3-mounting flange, 4-feed connection copper block, 5-metal feed line, 6-heat-resistant medium screw, 7-heat-resistant medium gasket, 8-metal reinforcing rib DETAILED DESCRIPTION

[0036] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0037] The present application provides a kind of metallization high-power log-periodic antenna unit, antenna whole adopts the full metal structure of dielectric plate, feed mode adopts metal feed line with air as medium, to improve the heat dissipation capacity and power capacity of antenna;Antenna oscillator gradually increases from high to low length, and the mirror image is folded inwards 45 degrees with the collection line as the central axis in the vertical plane, finally all oscillators are in two planes perpendicular to each other, on the basis, the bottom several groups of oscillator arms are further bent 90 degrees in the vertical direction, form "C" type oscillator arm, this structure effectively reduces the lateral size of antenna unit, can expand the antenna bandwidth to low frequency by using the coupling current between array elements in antenna array.The present application has the advantages of large antenna power capacity, antenna unit miniaturization and the like.

[0038] Example 1

[0039] Referring to Figure 1 、 Figure 2 、 Figure 3 , the metalized high-power log-periodic antenna unit provided in this embodiment 1 is composed of a metal antenna main body 1, a feed coaxial probe 2, a mounting flange 3, a feed connection copper block 4, a metal feed line 5, a heat-resistant medium screw 6, a heat-resistant medium gasket 7, and a metal reinforcing rib 8. The metal antenna main body 1 is vertically located on the mounting flange 3, the feed coaxial probe 2 is connected with the feed connection copper block 4 through the mounting flange 3, one end of the metal feed line 5 is connected with the feed connection copper block 4, and the other end is connected with the top end of the metal antenna main body 1 to feed the metal antenna main body 1.

[0040] Specifically, the metal antenna main body 1 is divided into inner and outer sides, i.e. inner metal antenna body and outer metal antenna body;The mounting flange 3 is divided into inner and outer sides, i.e. outer mounting flange and inner mounting flange;The inner metal antenna body is vertically located on the inner mounting flange, and the inner metal antenna body and the inner mounting flange are integrally processed;The outer metal antenna body is vertically located on the outer mounting flange, and the outer metal antenna body and the outer mounting flange are integrally processed.

[0041] Further, the outer metal antenna body and the inner metal antenna body are of the same structure, both comprising a collection line and antenna dipoles on both sides of the collection line; the antenna dipoles of the outer metal antenna body and the antenna dipoles of the inner metal antenna body form a 90° angle; the antenna dipoles gradually increase in length from high to low, and the bottom several groups of antenna dipoles are bent twice by 90 degrees to form "C" type dipole arms. The collection line of the outer metal antenna body and the inner metal antenna body is reserved with several threaded holes, which is convenient for inserting the heat-resistant medium screw 7.

[0042] Specifically, the feeding coaxial probe 2 adopts an N-type joint to improve the power capacity, extends from the bottom of the outer mounting flange, and is connected with the metal feeder 5 through the feeding copper block 4.

[0043] Further, the feeding coaxial probe 2 adopts an N-type joint, and the N-type joint medium extends from the outer mounting flange and is higher than the mounting flange, so as to avoid the contact between the mounting flange 3 and the metal feeder 5 and to play a role in avoiding short circuit.

[0044] Specifically, the feeding copper block 4 is arranged on the circular ring type pad of the metal feeder 5 on the outer mounting flange, the feeding coaxial probe 2 is inserted into the hole of the circular ring, and is connected with the metal feeder 5 and the feeding copper block 4 and is fixed by welding.

[0045] Specifically, the metal feeder 5 is fixed and installed in parallel to the collection line of the metal antenna body 1 through the heat-resistant medium gasket 7 and the heat-resistant medium screw 6, and extends to the shortest dipole end of the antenna top to form the antenna feeding.

[0046] Further, the metal feeder 5 extends to the antenna top, is bent twice by 90 degrees, is connected and fixed with the inner metal antenna body through the metal screw to form an electrical connection, feeds the antenna from the antenna top, and the length of the metal screw is 2-6 mm, which does not contact the outer collection line of the antenna to avoid short circuit.

[0047] Preferably, the length of the metal screw is 4.9 mm.

[0048] Specifically, the heat-resistant medium screw 6 passes through the metal feeder 5, the heat-resistant medium gasket 7, the collection line of the outer metal antenna body, the heat-resistant medium gasket 7, and the collection line of the inner metal antenna body, and is used to fix the metal feeder 5 and the metal antenna body 1.

[0049] Specifically, the heat-resistant medium gasket 7 is arranged between the metal feeder 5 and the outer main stem of the metal antenna body 1 and between the inner and outer main stems of the metal antenna body 1, and plays a supporting role. The thickness of the gasket between the metal feeder and the outer main stem of the metal antenna body is 1-5 mm, and the thickness of the gasket between the inner and outer main stems of the metal antenna body is 2-8 mm. The metal feeder, the inner and outer main stems of the metal antenna body are fixed and installed by the heat-resistant medium screw with a length of 3-15 mm.

[0050] Preferably, in this embodiment, the thickness of the spacer between the metal feed line 5 and the outer main body of the metal antenna is 2mm, and the thickness of the spacer between the inner and outer main bodies of the metal antenna is 4mm. The metal feed line and the inner and outer sides of the metal antenna are fixedly installed using heat-resistant screws with a length of 12mm.

[0051] Furthermore, the mounting flange 3 is provided with weight-reducing holes and screw holes on its surface, which serve to reduce weight and secure the bolts.

[0052] Preferably, the antenna body of the present invention is made of stainless steel, and the mounting flange 2, metal feed line 5, and metal antenna body 1 are all made of the same metal material, 304 stainless steel.

[0053] Furthermore, an arched metal reinforcing rib 8 is welded to the inner side of the antenna body. The reinforcing rib 8 is a long metal strip with an arched cross-section, which is welded and fixed to the inner metal antenna body assembly line, extending from the top of the antenna to the mounting flange to improve the antenna strength.

[0054] Furthermore, the inner and outer sides of the mounting flange are connected and fixed by metal screws and metal rings. The metal rings are placed between the inner and outer sides of the antenna body to provide support. The thickness of the metal rings is consistent with the thickness of the heat-resistant medium gasket 7 placed between the inner and outer sides of the antenna body, and the value range is 2-8mm. This ensures a tight connection and fixed spacing between the inner and outer sides of the antenna body. The length of the metal screws is 12mm.

[0055] Preferably, the metal ring is 4mm long and the metal screw is 12mm long.

[0056] Compared to traditional log-periodic antennas, the antenna of this invention uses a metal feed line 5 with air as the medium for feeding, and the thickness of the air medium is determined by electromagnetic simulation.

[0057] In this invention, the length of the antenna elements gradually increases from top to bottom, and the specific length of each group of elements is determined by electromagnetic simulation. The elements in the same group are perpendicular to each other, so that the overall antenna elements are distributed on two mutually perpendicular planes, effectively reducing the lateral length of the antenna.

[0058] like Figure 3 The figure shown is a dimensional diagram of the antenna in this embodiment 1. The overall height of the antenna is H = 490 mm, the overall width is W = 183 mm, and the overall length is L = 138 mm.

[0059] like Figure 4The simulation result comparison chart of the voltage standing wave ratio of the array and the independent unit of the antenna unit feeding port of the application is shown, and it can be seen from the chart that the working frequency of the independent antenna unit is 0.43GHz-2.0GHz and the working bandwidth is 4.6 times of the frequency under the condition that the voltage standing wave ratio is less than 2.5; after the 5x5 array is formed by the above-mentioned antenna units, the working frequency of the antenna unit is 0.3GHz-2.0GHz and the working bandwidth is widened to 6.6 times of the frequency by using the coupling current between the antenna units, thereby improving the working bandwidth of the whole antenna.

[0060] As shown in Figure 5 The simulation result chart of the gain of each frequency point of the antenna of the application varying with the frequency is shown, and it can be seen from the chart that the gain curve of the antenna unit increases with the increase of the frequency within the working bandwidth, and the gain range is 7.5dBi-9.5dBi.

[0061] Embodiment 2

[0062] The metalized high-power logarithmic periodic antenna array provided in the embodiment 2 comprises the above-mentioned plurality of metalized high-power logarithmic periodic antenna units, and the plurality of metalized high-power logarithmic periodic antenna units are arranged in an array; since the lateral size of the single metalized high-power logarithmic periodic antenna unit is reduced, the coupling current between the array elements is used to expand the antenna bandwidth to the low frequency in the antenna array.

[0063] The above is only a specific embodiment of the application, but the protection scope of the application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the application, and these modifications or replacements should be covered in the protection scope of the application.

Claims

1. A metallized high-power log-periodic antenna element, characterized in that, Includes a metal antenna body (1), a feed coaxial probe (2), a mounting flange (3), a feed connection copper block (4), and a metal feed line (5); The metal antenna body (1) includes an outer metal antenna body and an inner metal antenna body. The outer metal antenna body and the inner metal antenna body have the same structure, both including a connecting line and antenna elements located on both sides of the connecting line; the antenna elements of the outer metal antenna body and the antenna elements of the inner metal antenna body form a 90° angle. The antenna elements of the outer metal antenna body and the antenna elements of the inner metal antenna body gradually increase in length from high to low. The two 90-degree bends of the bottom group of antenna elements are mirror folds along the central axis at 45° and then vertical 90° bends twice to form C-shaped antenna arms. The metal feed line (5) uses air as the feed line medium, extends to the top of the antenna, bends twice at 90 degrees, and forms an electrical connection with the inner metal antenna body through metal screws, feeding the antenna from the top of the antenna; the metal feed line uses air as the medium and has a power capacity greater than 200W. The mounting flange (3) includes an outer mounting flange and an inner mounting flange, which are connected and fixed by metal screws and metal rings; wherein, the outer metal antenna body is vertically located on the outer mounting flange, and the inner metal antenna body is vertically located on the inner mounting flange. The coaxial feed probe (2) passes through the outer mounting flange and is connected to the feed connection copper block (4). One end of the metal feed line (5) is connected to the feed connection copper block (4), and the other end is connected to the top of the metal antenna body (1) to feed the metal antenna body (1).

2. The metallized high-power log-periodic antenna element according to claim 1, characterized in that, The power supply connection copper block (4) is welded to the pad on the outer mounting flange of the metal feed line (5).

3. The metallized high-power log-periodic antenna element according to claim 1, characterized in that, It also includes a heat-resistant medium screw (6) for fixing the metal feed line (5) and the metal antenna body (1).

4. The metallized high-power log-periodic antenna element according to claim 1, characterized in that, It also includes a heat-resistant dielectric pad (7) that provides support. The heat-resistant dielectric pad (7) includes an outer heat-resistant dielectric pad placed between the metal feed line (5) and the outer metal antenna body, and an inner heat-resistant dielectric pad placed between the metal feed line (5) and the inner metal antenna body.

5. The metallized high-power log-periodic antenna element according to claim 1, characterized in that, It also includes metal reinforcing ribs (8), which are long metal strips with an arched cross-section, fixed to the assembly line of the inner metal antenna body, and extending from the top of the antenna to the mounting flange.

6. The metallized high-power log-periodic antenna element according to claim 1, characterized in that, The mounting flange (3), metal feed line (5), and metal antenna body (1) are all made of the same metal material, 304 stainless steel.

7. The metallized high-power log-periodic antenna element according to claim 1, characterized in that, The mounting flange (3) has a variety of weight-reducing holes and through holes on its surface for weight reduction and screw fixing.

8. A metallized high-power log-periodic antenna array element, characterized in that, The antenna array includes a plurality of metallized high-power log-periodic antenna elements as described in any one of claims 1-7. The plurality of metallized high-power log-periodic antenna elements are arranged in an array. Due to the reduction in the lateral dimension of a single metallized high-power log-periodic antenna, the antenna bandwidth can be extended to low frequencies by utilizing the coupling current between the array elements in the antenna array.

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